Special Weather Statement, NWS Indianapolis, IN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
227 AM EDT SAT JUN 18 2011

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.

&&

.SYNOPSIS...
VERY WARM AND MOIST AIR WILL BE FOUND ACROSS CENTRAL INDIANA AS A
WARM FRONT LINGERS ACROSS THE AREA THROUGH THE WEEKEND. THIS WILL
RESULT IN MORE CHANCES FOR SHOWERS AND THUNDERSTORMS. THE BOUNDARY
IS EXPECTED TO PUSH NORTH ON SUNDAY...FOLLOWED BY A COLD FRONT. THE
ACTIVE WEATHER PATTERN WILL CONTINUE IN EARLY NEXT WEEK AS WARM AND
HUMID AIR REMAINS IN PLACE...PROVIDING DAILY CHANCES FOR STORMS AS A
COLD FRONT APPROACHES BY THURSDAY.

&&

.NEAR TERM /TODAY/...
FORECAST CHALLENGE IS POPS AND QPF.

ANALYSIS AS OF 2 AM THIS MORNING DEPICTS TWO FRONTAL
BOUNDARIES...ONE ACROSS NORTHERN INDIANA...AND ANOTHER ACROSS
SOUTHERN ILLINOIS. LATE FRI EVENING AN OUTFLOW BOUNDARY OVER CENTRAL
ILLIONOIS (FROM AN EARLIER MCS) FORMED ANOTHER COMPLEX OF STORMS
ACROSS SOUTH-CENTRAL ILLINOIS. THIS AREA OF SHOWERS AND
THUNDERSTORMS WILL *VERY* SLOWLY PROPAGATE TO THE SOUTHEAST THROUGH
16-18Z THIS AFTERNOON. RAPID REFRESH PEGS THIS COMPLEX TO MOVE
ACROSS OUR S/SW COUNTIES THROUGH EARLY TODAY...FOR THE MOST PART
STAYING SOUTH OF I-70. FOR THIS WILL PAINT IN LIKELY TO POSSIBLY
CATEGORICAL POPS FOR TODAY ACROSS THIS AREA. TO THE NORTH OF I-70
EXPECT ANY SHOWER/THUNDERSTORM ACTIVITY TO BE DIURNALLY GENERATED
AND PRETTY SCATTERED IN NATURE. LEFT IN CHANCE POPS ACROSS THE
NORTHERN TIER.

CONSIDERING THE HIGH INSTABILITY ACROSS THE REGION SPC CONTINUES TO
PLACE US IN A SLIGHT RISK FOR SEVERE WEATHER...WITH HAIL AND
DAMAGING WINDS AS THE MAIN THREATS. AN ADDITIONAL THREAT IS FLASH
FLOODING...SEEING AS PWATS ARE OVER 1.5" AND THESE STORMS ARE SLOW
MOVERS. WILL TRY TO KEY ON THESE THREATS IN THE HWO AND WX STORY.
ALSO WILL INCLUDE HEAVY RAIN MENTION AS ELEMENT IN THE GRIDS FOR
LIKELY+ POPS. CONSIDERING THE CLOUD COVER AND PRECIP STUCK CLOSE TO
MOS GUID FOR HIGHS IN THE MID 80S.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
BETTER CHANCES FOR WIDEPSREAD SHOWERS AND THUNDERSTORMS COME LATE
TONIGHT THROUGH SUNDAY AS A COLD FRONT APPROACHES THE AREA. THE
REGION REMAINS IN A SLIGHT RISK THROUGH THE REST OF THE WEEKEND.
PER SPC'S DAY 2 SEVERE WEATHER OUTLOOK WHICH BEGINS 12Z SUNDAY:
"EARLY IN THE PERIOD IT SEEMS LIKELY THAT A MID LEVEL SHORT WAVE
TROUGH WILL HAVE EJECTED TO A POSITION JUST EAST OF THE MS RIVER
OVER IL. THIS FEATURE WILL INDUCE A LLJ OVER THE PLAINS THAT
SHOULD VEER INTO THE MID MS VALLEY REGION AS THE PROGRESSIVE
TROUGH SHIFTS EAST. ALONG THE NOSE OF THIS LLJ AN ENHANCED ZONE OF
LOW LEVEL WARM ADVECTION SHOULD AID SEVERAL THUNDERSTORM CLUSTERS
OR MORE LIKELY A LARGER MCS OVER IL/IND. THIS ACTIVITY MAY PRODUCE
HAIL EARLY IN THE PERIOD BEFORE DIURNAL INFLUENCES ALLOW MORE
BOUNDARY LAYER UPDRAFTS TO INTENSIFY ALONG LEADING OUTFLOW."

ACTIVITY WILL LIKELY DEVELOP INTO A DAMAGING WIND THREAT LATER IN
THE DAY AS STEEPER LAPSE RATES DEVELOP AND DEEP LAYER SHEAR
PROFILES SUPPPORT 35 TO 45 KT. FEEL CONFIDENT ENOUGH IN GUIDANCE
TO BUMP POPS BACK UP TO LIKELY FOR SUNDAY FOR THE MAJORITY OF THE
FORECAST AREA. FOR NOW WILL OMIT MENTION OF ANY SPECIFIC SEVERE
THREATS IN THE GRIDS AND STICK TO HIGHLIGHTING IN THE HWO. LATER
SHIFTS MAY DECIDE TO GET MORE SPECIFIC AS WE GET CLOSER TO EVENT.
BY SUNDAY NIGHT ACTIVITY SHOULD BE WINDING DOWN ACROSS CENTRAL
INDIANA. LEFT IN CHANCE POPS ACROS THE EASTERN COUNTIES BUT FOR
THE MOST PART GREATER THREAT WILL BE EARLIER IN THE DAY.

IN TERMS OF TEMPS STUCK CLOSE TO MOS DURING THIS PERIOD...ONLY GOING
SLIGHT WARMER TONIGHT.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MODELS AGREE ABOUT ESSENTIALS. THAT IS...WARM HUMID AIR IN
SOUTHERLY FLOW INTO MIDWEEK. COOLER BEHIND A FRONT LATER NEXT
WEEK.

BETWEEN THE WARM UNSTABLE AIR AT FIRST...AND THEN THE FRONT...WE
WILL HAVE AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS MOST OF THE
TIME. I AM NOT MUCH DIFFERENT FROM HPC POPS ON THIS.

TEMPERATURE FORECAST RELATIVELY SIMPLE EARLY IN PERIOD IN WARM
FLOW. BASICALLY EXTRAPOLATING FROM WHAT IS IN SOUTHERN STATES NOW.
BEGINNING WEDNESDAY THINGS GET MORE UNCERTAIN. MUCH DEPENDS ON
TIMING OF INCOMING FRONT AND HARD TO BEAT MOS. HPC TEMPS SEEM TO
CAPTURE THESE CONCEPTS. I DID NOT CHANGE THEIR GUIDANCE MUCH.

&&

.AVIATION /DISCUSSION FOR THE 180600Z TAFS/...
SHOWERS AND SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP
ACROSS ILLINOIS AND ATTEMPT TO WORK THEIR WAY INTO INDIANA.
FORCING REMAINS CONCENTRATED ACROSS SOUTHERN HALF OF THE AREA...SO
BELIEVE KHUF AND KBMG HAVE THE BEST CHANCES FOR PRECIPITATION
OVERNIGHT.

WILL GO TEMPO SHOWERS AT KHUF AND KBMG WITH VCTS AND/OR CB MENTION
SINCE ORGANIZED STORMS MAY REMAIN JUST SOUTH AND WEST OF THE AREA.
WILL MONITOR CLOSELY AND AMEND AS NEEDED. AT KIND WILL GO WITH VCSH
AND CB MENTION. KLAF LOOKS TO BE FAR ENOUGH NORTH FOR NO MENTION
EARLY IN THE PERIOD.

CLOUD COVER SHOULD KEEP MOST FOG AT BAY...BUT IF BREAKS DEVELOP MVFR
FOG COULD RAPIDLY DEVELOP.

OTHERWISE...COULD SEE SOME MORE STORMS AFTER DAYBREAK AND THROUGH
SATURDAY NIGHT WITH VARIOUS UPPER WAVES MOVING EAST ACROSS CENTRAL
INDIANA AND INTERACTING WITH AN UNSTABLE ATMOSPHERE. TIMING AND
COVERAGE IN QUESTION...SO WILL JUST GO WITH CB GROUPS THROUGH THE
TAF PERIOD. CONDITIONS SHOULD BE VFR AND WINDS LESS THAN 15 KNOTS
AWAY FROM THUNDERSTORMS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....JK
AVIATION...50/MK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
303 AM EDT SAT JUN 18 2011

INZ021-028>031-035>049-057-190715-
CARROLL-WARREN-TIPPECANOE-CLINTON-HOWARD-FOUNTAIN-MONTGOMERY-
BOONE-TIPTON-HAMILTON-MADISON-DELAWARE-RANDOLPH-VERMILLION-PARKE-
PUTNAM-HENDRICKS-MARION-HANCOCK-HENRY-RUSH-
303 AM EDT SAT JUN 18 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS WILL OCCUR ACROSS CENTRAL INDIANA TODAY
AND TONIGHT. THERE IS A SLIGHT RISK THAT SOME OF THESE STORMS MAY
BECOME SEVERE...WITH LARGE HAIL...DAMAGING WINDS...AND VERY HEAVY
RAINFALL AS THE MAIN THREATS...IN ADDITION TO LIGHTNING WHICH IS A
HAZARD WITH ANY THUNDERSTORM.

LOW LAND FLOODING WILL OCCUR ALONG PORTIONS OF THE WABASH AND
LOWER WHITE RIVER. SEE LATEST FLOOD STATEMENTS FOR MORE DETAILS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH THURSDAY.

THERE IS A CHANCE OF THUNDERSTORMS SUNDAY THROUGH THURSDAY OF
NEXT WEEK. IN ADDITION...THERE IS A SLIGHT RISK OF SEVERE
THUNDERSTORMS ON SUNDAY WITH LARGE HAIL AND DAMAGING WINDS AS THE
MAIN THREATS. LOCALLY HEAVY RAIN IS ALSO POSSIBLE.

LOW LAND FLOODING MAY OCCUR ALONG PORTIONS OF THE WABASH AND
LOWER WHITE RIVER THROUGH THE WEEKEND. SEE LATEST FLOOD STATEMENTS
FOR MORE DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO CALL IN WITH ANY SEVERE WEATHER OR
FLOODING REPORTS TODAY AND TONIGHT...IN ADDITION TO SUNDAY.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)

INZ051>056-060>065-067>072-190715-
VIGO-CLAY-OWEN-MORGAN-JOHNSON-SHELBY-SULLIVAN-GREENE-MONROE-BROWN-
BARTHOLOMEW-DECATUR-KNOX-DAVIESS-MARTIN-LAWRENCE-JACKSON-JENNINGS-
303 AM EDT SAT JUN 18 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS WILL OCCUR ACROSS CENTRAL INDIANA TODAY
AND TONIGHT. THERE IS A SLIGHT RISK THAT SOME OF THESE STORMS MAY
BECOME SEVERE...WITH LARGE HAIL...DAMAGING WINDS...AND VERY HEAVY
RAINFALL AS THE MAIN THREATS...IN ADDITION TO LIGHTNING WHICH IS A
HAZARD WITH ANY THUNDERSTORM. LOCALIZED FLASH FLOODING IS
POSSIBLE IN ANY OF THE SLOW MOVING THUNDERSTORMS.

LOW LAND FLOODING WILL OCCUR ALONG PORTIONS OF THE WABASH AND
LOWER WHITE RIVER. SEE LATEST FLOOD STATEMENTS FOR MORE DETAIL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH THURSDAY.

THERE IS A CHANCE OF THUNDERSTORMS SUNDAY THROUGH THURSDAY OF
NEXT WEEK. IN ADDITION...THERE IS A SLIGHT RISK OF SEVERE
THUNDERSTORMS ON SUNDAY WITH LARGE HAIL AND DAMAGING WINDS AS THE
MAIN THREATS. LOCALLY HEAVY RAIN IS ALSO POSSIBLE.

LOW LAND FLOODING MAY OCCUR ALONG PORTIONS OF THE WABASH AND
LOWER WHITE RIVER THROUGH THE WEEKEND. SEE LATEST FLOOD STATEMENTS
FOR MORE DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO CALL IN WITH ANY SEVERE WEATHER OR
FLOODING REPORTS TODAY AND TONIGHT...IN ADDITION TO SUNDAY.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)

SMF

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
318 AM EDT SAT JUN 18 2011

INZ067-068-180800-
DAVIESS-KNOX-
318 AM EDT SAT JUN 18 2011

...STRONG THUNDERSTORM ADVISORY FOR SOUTHWESTERN DAVIESS AND KNOX
COUNTIES UNTIL 400 AM EDT...

AT 316 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM BRIDGEPORT TO
PATOKA...AND MOVING NORTHEAST AT 25 MPH.

HAIL UP TO THE SIZE OF PENNIES IS EXPECTED WITH THESE STORMS...ALONG
WITH HEAVY RAIN.

THESE STORMS WILL BE NEAR...
DECKER AROUND 325 AM EDT...
VINCENNES UNIVERSITY AND VINCENNES AROUND 340 AM EDT...
MONROE CITY AROUND 350 AM EDT...
BRUCEVILLE AROUND 355 AM EDT...
OAKTOWN...BICKNELL AND WHEATLAND AROUND 400 AM EDT...

THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS... FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED
ROADWAY.

&&

LAT...LON 3848 8776 3851 8765 3855 8767 3864 8763
      3869 8753 3874 8751 3890 8755 3890 8723
      3853 8715 3855 8721 3850 8730 3854 8735
      3851 8737 3854 8740 3853 8746 3849 8749
      3849 8757 3844 8760 3845 8766 3842 8771
TIME...MOT...LOC 0718Z 243DEG 22KT 3876 8777 3843 8750

50